Commercial aircraft include onboard power systems typically including a power generation system and a power distribution system. The power systems are used to generate and distribute power during operation of the aircraft, and the power is used to power onboard electronic systems. As part of the power distribution system, electric contactors control power flow over a series of power distribution buses. The contactors control the flow of current in the bus bars, and mechanically switch current on or off as needed by the power systems.
Due to the switching within the contactor modules, the contactors generate heat during operation of the power distribution system. Heat from the contactor leads is conducted to external power distribution bus bars and from the external power distribution bus bars into the ambient atmosphere. To accommodate this cooling feature, the external power distribution bus bars are sized large enough that the heat can be properly dissipated. An additional step utilized to facilitate the additional heat dissipation requirements is the utilization of copper, in place of the lighter weight aluminum, as the primary metal of the bus bars. Utilization of a heavier material increases the weight of the bus bar and the overall power distribution assembly.